drivers/crypto/ccp/tee-dev.h

   1 /* SPDX-License-Identifier: MIT */
   2 /*
   3  * Copyright (C) 2019,2021 Advanced Micro Devices, Inc.
   4  *
   5  * Author: Rijo Thomas <Rijo-john.Thomas@amd.com>
   6  * Author: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
   7  *
   8  */
   9
  10 /* This file describes the TEE communication interface between host and AMD
  11  * Secure Processor
  12  */
  13
  14 #ifndef __TEE_DEV_H__
  15 #define __TEE_DEV_H__
  16
  17 #include <linux/device.h>
  18 #include <linux/mutex.h>
  19
  20 #define TEE_DEFAULT_TIMEOUT             10
  21 #define MAX_BUFFER_SIZE                 988
  22
  23 /**
  24  * enum tee_ring_cmd_id - TEE interface commands for ring buffer configuration
  25  * @TEE_RING_INIT_CMD:          Initialize ring buffer
  26  * @TEE_RING_DESTROY_CMD:       Destroy ring buffer
  27  * @TEE_RING_MAX_CMD:           Maximum command id
  28  */
  29 enum tee_ring_cmd_id {
  30         TEE_RING_INIT_CMD               = 0x00010000,
  31         TEE_RING_DESTROY_CMD            = 0x00020000,
  32         TEE_RING_MAX_CMD                = 0x000F0000,
  33 };
  34
  35 /**
  36  * struct tee_init_ring_cmd - Command to init TEE ring buffer
  37  * @low_addr:  bits [31:0] of the physical address of ring buffer
  38  * @hi_addr:   bits [63:32] of the physical address of ring buffer
  39  * @size:      size of ring buffer in bytes
  40  */
  41 struct tee_init_ring_cmd {
  42         u32 low_addr;
  43         u32 hi_addr;
  44         u32 size;
  45 };
  46
  47 #define MAX_RING_BUFFER_ENTRIES         32
  48
  49 /**
  50  * struct ring_buf_manager - Helper structure to manage ring buffer.
  51  * @ring_start:  starting address of ring buffer
  52  * @ring_size:   size of ring buffer in bytes
  53  * @ring_pa:     physical address of ring buffer
  54  * @wptr:        index to the last written entry in ring buffer
  55  */
  56 struct ring_buf_manager {
  57         struct mutex mutex;     /* synchronizes access to ring buffer */
  58         void *ring_start;
  59         u32 ring_size;
  60         phys_addr_t ring_pa;
  61         u32 wptr;
  62 };
  63
  64 struct psp_tee_device {
  65         struct device *dev;
  66         struct psp_device *psp;
  67         void __iomem *io_regs;
  68         struct tee_vdata *vdata;
  69         struct ring_buf_manager rb_mgr;
  70 };
  71
  72 /**
  73  * enum tee_cmd_state - TEE command states for the ring buffer interface
  74  * @TEE_CMD_STATE_INIT:      initial state of command when sent from host
  75  * @TEE_CMD_STATE_PROCESS:   command being processed by TEE environment
  76  * @TEE_CMD_STATE_COMPLETED: command processing completed
  77  */
  78 enum tee_cmd_state {
  79         TEE_CMD_STATE_INIT,
  80         TEE_CMD_STATE_PROCESS,
  81         TEE_CMD_STATE_COMPLETED,
  82 };
  83
  84 /**
  85  * enum cmd_resp_state - TEE command's response status maintained by driver
  86  * @CMD_RESPONSE_INVALID:      initial state when no command is written to ring
  87  * @CMD_WAITING_FOR_RESPONSE:  driver waiting for response from TEE
  88  * @CMD_RESPONSE_TIMEDOUT:     failed to get response from TEE
  89  * @CMD_RESPONSE_COPIED:       driver has copied response from TEE
  90  */
  91 enum cmd_resp_state {
  92         CMD_RESPONSE_INVALID,
  93         CMD_WAITING_FOR_RESPONSE,
  94         CMD_RESPONSE_TIMEDOUT,
  95         CMD_RESPONSE_COPIED,
  96 };
  97
  98 /**
  99  * struct tee_ring_cmd - Structure of the command buffer in TEE ring
 100  * @cmd_id:      refers to &enum tee_cmd_id. Command id for the ring buffer
 101  *               interface
 102  * @cmd_state:   refers to &enum tee_cmd_state
 103  * @status:      status of TEE command execution
 104  * @res0:        reserved region
 105  * @pdata:       private data (currently unused)
 106  * @res1:        reserved region
 107  * @buf:         TEE command specific buffer
 108  * @flag:        refers to &enum cmd_resp_state
 109  */
 110 struct tee_ring_cmd {
 111         u32 cmd_id;
 112         u32 cmd_state;
 113         u32 status;
 114         u32 res0[1];
 115         u64 pdata;
 116         u32 res1[2];
 117         u8 buf[MAX_BUFFER_SIZE];
 118         u32 flag;
 119
 120         /* Total size: 1024 bytes */
 121 } __packed;
 122
 123 int tee_dev_init(struct psp_device *psp);
 124 void tee_dev_destroy(struct psp_device *psp);
 125
 126 #endif /* __TEE_DEV_H__ */